BAGHDAD, Oct. 12 -- The Iraqi government on Sunday ordered security forces to increase protection for Christians in northern Iraq, where thousands have fled their homes after a wave of killings and threats.

Eleven to 15 Christians have been slain in the past few days in Mosul, according to reports from church and political leaders. Fighters from al-Qaeda in Iraq, a mostly homegrown extremist group, have resisted U.S. efforts to oust them from the area, which remains among the most violent in Iraq.

"These attacks have never been seen in Mosul city. Centuries and centuries we were living together," a parliamentary deputy, Yonadam Kanna, said in an interview before he and other Christian politicians met Sunday with Prime Minister Nouri al-Maliki.

Maliki's office said in a statement that he was ordering the Iraqi army and police in the Mosul area "to provide protection for members of this community" and that the security forces would "target the terrorist groups" behind the attacks.

Christians make up about 3 percent of Iraq's population of 28 million, about half the size of the community before the 2003 U.S.-led invasion, according to church leaders and human rights organizations. Many Christians left the country after being kidnapped or harassed by Islamist extremists and criminals.

Some Christians had moved in recent years to northern Iraq, which appeared safer. But in February, the archbishop of Mosul's Chaldean Catholic community, Paulos Faraj Rahho, was kidnapped. His body turned up weeks later.

A new wave of panic has spread through the Christian community in Mosul in recent days as several of its members appeared to be targeted for their faith. Among those killed were a 15-year-old boy and a man in a wheelchair. In the most recent incident, armed men burst into a music store in the city Sunday and killed its Christian owner, police said.

Anti-Christian leaflets have appeared in the city, signed by a group called the Iraqi Islamic State. And on Saturday night, armed men blew up three empty houses belonging to Christians in the al-Sukar neighborhood, local authorities said. That fed an exodus that has swelled to at least 1,000 families, said Duraid Kashmulah, the governor of Nineveh province, which includes Mosul.

Kashmulah blamed "al-Qaeda and their followers, and people who want to destroy relations between the people of Mosul," historically known for their religious tolerance.

Others suggested the killings were politically motivated. They noted that Christians have held protests since the national parliament passed a provincial elections law last month that eliminated quotas in parliament for religious minorities. President Jalal Talabani has urged legislators to restore the guarantees, and they are studying the matter.

A Chaldean Christian bishop, Gabriel Gordiz Toma, who is from an area outside Mosul, said he suspected that the assailants could be trying to weaken Christians before local elections expected in January. But he said he did not understand why the demonstrations could have provoked the attacks.

"Who could retaliate this way, when we are just demanding our rights?" he said.